/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.solr.analytics.value;

import org.apache.solr.analytics.facet.compare.FacetResultsComparator;

/**
 * A single-valued analytics value that can be compared and used to sort a facet.
 */
public interface ComparableValue extends AnalyticsValue {
  /**
   * Create an entry comparator used to sort the facet-value buckets of a facet.
   * 
   * @param expression the name of the expression in the results array
   * @return a comparator to sort the buckets with
   */
  FacetResultsComparator getObjectComparator(String expression);
}